Winding for dynamo-electric machines



H. W. TAYLOR AND F. H. CLOUGH.

WINDING FOR DYNAMO ELECTRIC MACHINES.

' APPLICATION FILE!) DEC- 9,1920.

Hen.

der'ICk Clou th, M M

Their Attovney.

PatentedSept. 6,1921.

I I I Inventors.

\W. Teylov,

UNITED STATES PATENT OFFICE.

HENRY WILLIAM TAYLOR, OF BILTON, AND FREDERICK HORTON CLOUGH, OF RUGBY,

ENGLAND, ASSIGNORS T0 GENERAL ELECTRIC COMPANY, A CORPORATION NEW YORK.

WINDING FOR DYNAMO-ELECTRIC MACHINES.

Patented Sept. 6, 1921.

Application filed December 9, 1920. Serial No. 429,500.

To allwkom it may concern:

Be it known that we, HENRY WILLIAM TAYLOR and FREDEnrcK HORTON CLoUcH,subjects of the King of Great Britain, residing, respectively, atBilton, county of Warwickshire, England, and at Rugby, county ofWarwickshire, England, have invented certain new and useful Improvementsin Windings for DynamdElectric Machines, (for which I have filed anapplication in England, Dec. 2, 1919, No. 30,063,) of which thefollowing is a specification.

The present invention relates to dynamo electric machines and moreparticularly to armature windings for alternating-current machines.

In large alternating-current generators in which the windings dis osedin the armature slots consist of'con uctors of considerable depth,magnetic flux across the slot resulting from the current in theconductors gives rise to a parasitic voltage within the conductors whichis liable to cause local currents and thereby produce heating of theconductors and an inefficient use of the copper in the armature.

It has hitherto been proposed to limit the current which will flow as aresult of these parasitic voltages first, by dividing the con ductorinto a number of separate multiple bars or sections and secondly, bycontinuing these laminations of the complete conductor throughout anentire coil or winding and so connecting the ends that the order of sections in the'conductors in the upper portion of the coil is the reverseof the order of the sections in the lower portion of the coil.

It will be understood that such an arrangement limits only the parasiticcurrents which flow between the various sections and not parasiticcurrents which flow locally in each section owing to its own thickness.It will also be understood that the maximum possible number of sectionsis limited by the number of turns in the complete winding. It is foundtherefore that on large machines with very deep conductors, the localcurrents which flow even when these provisions are made are stillexcessive and impose limitations on the design of the machine.

One object of the present invention is to the'sections in turn beingformed of a pluupon the current in the units below the one in question.The flux across such a unit may therefore be considered as consisting ofa variable element due to the current in the unit and also of a numberof constant elements which depend upon the. number of units below theunit in question, as, for example, the second unit is subjected to theinfluence of one constant element of flux, the third unit is subjectedto the influence of two constant elements of flux, the fourth unit tothree constant elements of flux, etc. By the'term constant I mean thatthe flux due to the current in the units below is uniformly distributedthroughout the unit in question. A variable element of flux, however, isnot uniformly distributed but, as above stated, increases in densityfrom the bottom of the unit. It is to be noted that from time to time asthe current changes the value of both the constant and variable elementsalso changes. At the time of maximum current the total quantity of fluxexisting in any unit, that is, the sum of the constant and variableelements is a'maxiinum and this is the flux which upon the rise ofcurrent has cut the bottom of the conducting unit but not the top of theunit. Regardless of the total quantity of flux which is moved upwardthrough the unit it is this flux only which causes the voltage to be setup tending to cause the parasitic current to flow between the topandbottom of the unit. A further object of the present invention is toprovide a dyna'moelectric machine constructed as above set forth,wherein the sections and laminations are so connected that the voltagedue to these flux elements shall be opposed to one another and the eddycurrents which flow as a result of these voltages reduced to a minimum.

, With these and other objects in View, reference will be had to theaccompanying drawings wherein Figure 1 represents diagrammatically aplurality oi armature slots which are adapted to receive a winding offour turns per phase, the conductor being divided into four sections,each of which sections is composed of three laminations; Fig. 2 is afull development of the winding illustrated in Fig. 1.

Referring to Figs. 1 and 2, A to H represent a series of armature slots,Jr to D being located beneath one field poleand slots E to H beinglocated beneath a pole of the opposite sign. Thefour sections of theconductor as illustrated in Fig. 2 are located in the lower halves ofslots A to D, occupying positions 1 to i therein and in the upper halvesof slots E to H, occupying positions 5 to S. It will be noted from Fig.1, which shows the positions occupied by one section, that this sectionpasses from position 1 in slot A to position 8 in slot E, hence back toposition 2 inslot B, to position 7 in slot F and so on until position 5in slot H is reached. This section therefore occupies successivepositions. in each group of slots A to D and to H and on completion ofthe winding has occupied all of the positions 1 to S. The section whichlies in position 2 in slot A passes from that position to position 7 inslot E, back to position 3 of slot '13 and continuing likewise occupiessuccessive positions until all positions 1 to 8 have been occupied. Eachof the remaining sec tions occupy successive positions in like manner.It will be noted that the order of the sections in each of slots E to His the reverse of the order in the corresponding slots A. to D.

Each of the sections is composed of three laminations, a, 7) and c, andit may be ob served that the laminations of the section which is shownin Fig. 1 appear in the reverse order in positions 2, 3, 6 and 7 fromthe order in which they appear in positions 1, 4, 5 and 8. It islikewise true of the laminations of all sections that occupy a reverseorder in positions 2, 3, 6 and 7 from the order in which they occur inpositions 1, 4t, 5 and 8. All sections and laminations are directlyconnected togetherin multiple at the ends of the winding.

Considering the flux elements as above defined, acting upon the sectionshown in Fig. 1, it will be observed that for positions 1, 1-, 5 and 8the constant flux elements are 0+3+t+7zls and for positions 2, 3, 6 and7 they are -125-6:14E. The

variable flux elements, that is, the elements of flux existing withinthe section by reason of the current within that section, are forpositions 1, 1, 5 and 8 1+1|1+1: i and for positions 2, 3, 6 and 71l11:4.

The constant flux elements therefore neutralize each other as do thevariable flux elements, with the result that the eddy cur rents whichtend to flow within sections are practically eliminated.

lVhile we have termed the members represented by a, Z) and 0laminations, it is apparent that they may be considered merely asconducting units which in themselves may be composedof yet smallersubdivisions of the conductor.

What we claim as new and desire to secure by Letters Patent of theUnited States, is,

1. An armature provided with slots and a winding located therein, saidwinding comprising a plurality of sections, each of which is composed ofa group of laminations, said sections and laminations being eachinsulated from one another throughout the winding and connected at theirends in multiple, each section from one end to the other of said windingoccupying successively all positions within a slot and the order of thelaminations within each section being reversed in certain of the halfturns from their order in the remaining half turns of the section,whereby the total number of flux elements linking the laminations ofeach section in one direction is equal and opposite to the total numberof flux elements linking the laminations of each section in the oppositedirection.

2, An armature provided with slots and a winding located therein, saidwinding comprising a plurality of sections, each of which is composed ofa group of laminations corresponding in number to the turns of thewinding, said sections and laminations being insulated from one anotherthroughout the winding and connected at their ends in multiple, saidsections occupying different relative positions in successive turns ofthe winding and said laminations occupying different relative positionswithin the several halt turns so that the total number of constant fluxelements linking the laminations of each section in one direction isequal and opposite to the totalnumber of constant flux elements linkinglaminations of each section in the opposite direction.

In witness whereof, we have hereunto set our hands this seventeenth dayof November, 1920.

' HENRY WILLIAM TAYLOR.

FREDERICK HORTON CLOUGH.

itnesses to the signature of Henry Villiam Taylor:

M. E. TAYLOR, V. M. SHARLAND.

Vitnesses to the signature of Frederick Horton Clough:

J. A. Fosrnn, D. VVHITE.

